How to test your mash with iodine???

Can someone please give me the lowdown on how to test your mash conversion with iodine. Can you use any iodine that can be found at the drugstore?

The idea is that iodine will turn a purplish color in the presence of starch. Any iodine should do, if you have Iodophor around that'll work too!

What I usually do is get a tablespoon or so of my mash liquid and put it on a clean white plate then put a drop of iodine in the middle. If the iodine stays brownish, all the starch has been converted, if it turns purple the enzymes have got some work to do still.

I'd do an experiment: make up a starchy solution (add some flour to water, or maybe make a "grain tea" if you have a little bit of base malt kicking around) and add the iodine so you know what to expect.

Perfect instructions! One other thing, though- make sure you have only wort and not grain when you test. The grain can interfere with a negative test.

I use a toothpick to "dot" the iodine onto the wort. You don't need much at all. If it stays the same color, the starch as been converted. If you see a color change, it hasn't been converted.

I liked Kai's big chalk method. he used a big piece of chalk and drops a drop of wort on it from the mash paddle and then place the iondine on it.

Great. Thanks guys.